Arthur Cecil Pigou

Arthur C. Pigou, a British economist, is best known for his work in welfare economics. In his book The Economics of Welfare Pigou developed alfred marshall’s concept of externalities, costs imposed or benefits conferred on others that are not taken into account by the person taking the action. He argued that the existence of externalities is sufficient justification for government intervention. If someone is creating a negative externality, such as pollution, for instance, he is engaging in too much of the activity that generated the externality. Pigou advocated a tax on such activities to discourage them. Someone creating a positive externality—say, by educating himself and making himself more interesting or useful to other people—might not invest enough in education because he would not perceive the value to himself as being as great as the value to society. Pigou advocated subsidies for activities that created such positive externalities. These are now called Pigovian taxes and subsidies, respectively.